Species of Canacidaesensu lato of Brazil are reviewed, including the subfamilies Canacinae and Tethininae. Included are seven species in five genera with two species, Nocticanace austra and Nocticanace packhamorum, from southern Brazil being newly described. To facilitate identification, we have included keys and diagnose to taxa at all levels.

The [taxon-name: Canacidae] of Brazil have never been treated comprehensively even though specimens are often abundant and species are relatively diverse on beaches of this large Neotropical and biologically diverse country where life on the beach is often a way of life. This deficiency is not uncommon, however, and characterizes many insect families occurring on beaches, especially groups that have relatively few species, that are collected infrequently despite being common locally, and that have no species of known economic importance. Although the [taxon-name: Canacidae] lack pestiferous species, study of the family is warranted, as its species comprise an important component of the beach fauna. Beyond satisfying the immediate objective--a taxonomic conspectus of the Brazilian fauna--we are also seeking to discover and contribute toward other aspects of their natural history, such as their distribution, historical biogeography, ecology, behavior, and biodiversity. The underlying basis for all of these studies, however, is the taxonomy of the included taxa.

True flies of the family [taxon-name: Canacidae] occur in cool-temperate and tropical zones of the world, primarily on or near seashores with oceanic climates. A few species are found inland, usually in saline or alkaline environments, but occasionally in meadow-like habitats or in freshwater, such as the streams of Hawaii. Worldwide there are 308 species in the family (6 subfamilies, 27 genera) (Munari and Mathis 2010; Munari and Stuke 2011), and from Brazil, we now have records of seven species and others are likely to be discovered here. The species of Brazil are in two subfamilies and five genera. Although the [taxon-name: Canacidae] of Brazil have never been treated comprehensively until now, the research published here had its genesis and basis in the works of others, as noted in the synonymy for the taxonomic categories from family to species that are included here. The classification adopted here is intended to provide perspective for this faunistic study and to serve as the organizational structure for this paper.

The historical record concerning [taxon-name: Canacidae] from Brazil began slightly more than a century ago when Williston (1896) described two species ([taxon-name: Anthomyza cinerea] (= [taxon-name: Tethina willistoni] (Melander)) and [taxon-name: Rhicnoessa xanthopoda]) from specimens collected on the island of St. Vincent (Caribbean). During the intervening 100 years, another species, [taxon-name: Tethina albula] (Loew), had been reported from Brazil (Melander 1952; Mathis and Munari 1996) but was apparently based on a misidentification. We have not examined any specimens of [taxon-name: Tethina albula], and all specimens that are light colored, including mostly pale setae, are [taxon-name: Tethina willistoni]. Herein we review seven species in five genera that occur in Brazil. Three of these genera are reported for the first time from Brazil, as are four of the species. Two species, [taxon-name: Nocticanace austra] and [taxon-name: Nocticanace packhamorum], are new to science and are described in this paper.

Because many species of [taxon-name: Canacidae] are widespread, especially those that occur in coastal marine habitats, we have examined most New World species, including primary types, to determine the correct identifications and valid names for the included species.

Materials and methods

The descriptive terminology for external structures and many internal structures follows that published in the Manual of Nearctic [taxon-name: Diptera] (J. F. McAlpine 1981). For structures of the male terminalia, however, we have adopted the terminology that Cumming et al. (1995) have suggested. Because specimens are small, usually less than 5.0 mm in length, study and illustration required use of dissecting and compound microscopes. Two wing ratios used in the descriptions are defined below (ratios are averages of three specimens: the largest, smallest, and one other).

1. Costal section ratios are the relative straight line distances between the apices of the subcosta and vein R1: apices of R1 and R2+3; and apices R2+3 and R4+5.

2. M vein ratio: the straight line distance along M between crossveins (r-m and dm-cu)/distance apicad of crossvein dm-cu.

Label data from each specimen were recorded and listed alphabetically according to country, state or province, county, and specific locality, such as city. As available, date of collection, collector, sex, and specimen location were listed. Label data from holotype specimens were recorded exactly, and clarifying information, such as script style and label color, is enclosed within brackets.

Dissections of male and female genitalia and descriptions were performed using the method of Clausen and Cook (1971) and Grimaldi (1987). Microforceps were used to remove abdomens, which were macerated in a potassium or sodium hydroxide solution. Cleared genitalia were rinsed in distilled water and 70% ethanol and then transferred to glycerin for observation. If necessary for proper orientation, the genitalia were transferred from glycerin to glycerin jelly. The glycerin jelly was heated, and the genitalia appropriately oriented. After cooling, the embedded specimen became immobilized. Abdomens were placed in an attached plastic microvial filled with glycerin and attached to the pin supporting the remainder of the insect from which it was removed. For freshly caught specimens, we recommend that the epandrium and associated structures of the male terminalia be teased open, thus allowing examination of these structures and identification of the species without need of dissection.

Species’ descriptions are composite and not based solely on the holotypes, and paired structures are described in the singular except where the context makes this inappropriate.

Although most specimens for this study are in the Department of Zoology, Universidade Federal do Paraná, Curitiba, Brazil (DZUP) and the National Museum of Natural History, Smithsonian Institution, Washington, D. C. (USNM), we also studied numerous specimens that were borrowed and are deposited elsewhere. These include (acronyms that are used in the text are noted first):

BPBM

Bernice P. Bishop Museum, Honolulu, Hawaii, USA

BMNH

The Natural History Museum (former British Museum (Natural History)), London, United Kingdom

Our concept of [taxon-name: Canacidae] includes what had been considered as two families, the [taxon-name: Canacidae] and [taxon-name: Tethinidae]. At the familial level, J. F. McAlpine (1989: 1472) identified five synapomorphies that link [taxon-name: Canacidae] with [taxon-name: Tethinidae] and noted that “...these are clear indications of a sister-group relationship between them ... and may even indicate that they are subgroups of a single family.” Other authors (Hennig 1958; Griffiths 1972; McAlpine 1982; Freidberg 1995) have also suggested a relationship with the family [taxon-name: Tethinidae], and Griffiths (1972) further noted some affinities with the [taxon-name: Chloropidae] and [taxon-name: Milichiidae]. According to J. F. McAlpine’s (1989) cladogram, which included an analysis of 25 characters for the families [taxon-name: Canacidae] and [taxon-name: Tethinidae], the superfamily [taxon-name: Carnoidea] (= [taxon-name: Chloropoidea]) comprises the families with the following relationships in parenthetic notation: (([taxon-name: Australimyzidae], [taxon-name: Braulidae]) [taxon-name: Carnidae])(([taxon-name: Tethinidae], [taxon-name: Canacidae])(([taxon-name: Milichiidae], [taxon-name: Risidae]) (([taxon-name: Cryptochetidae], [taxon-name: Chloropidae])))).

More recently, Buck (2006) and D. K. McAlpine (2007) provided rather compelling character evidence, substantiating that these two families are closely associated, and more specifically that the [taxon-name: Canacidae]sensu stricto are an included lineage within the [taxon-name: Tethinidae]. Thus, not to include the [taxon-name: Canacidae] within the [taxon-name: Tethinidae] would render the [taxon-name: Tethinidae] as a paraphyletic family. Buck and D. K. McAlpine cited ten synapomorphies that corroborate the monophyly of the family [taxon-name: Canacidae]sensu lato (the family-group name [taxon-name: Canacidae] is older than [taxon-name: Tethinidae]). These synapomorphies are (only derived state cited): (1) Precoxal bridge present; (2) anepisternum with enlarged, dorsally curved setae at posteroventral corner; (3) vein A2 long, present as a fold; (4) male sternite 6 reduced and divided medially; (5) male tergite 6 fused with sternite 8, forming a symmetrical pregenital sclerite; (6) male sternite 7 lost; (7) postgonites firmly connected laterally to base of phallapodeme, distinctly anterior to basiphallus; (8) hypandrium forming a sheath or phallic mantle around the postgonite and basiphallus; (9) cuticle of larva with covering of fine spicules, and (10) halobiontic in habitat preference, secondarily in freshwater habitats. Buck (2006) further suggested that the sister group to [taxon-name: Canacinae]sensu stricto is the subfamily [taxon-name: Apetaeninae] and not [taxon-name: Zaleinae] and provided four characters as corroborative evidence for this relationship: (1) antennae broadly separated, inserted more or less on protuberant facial tubercles; (2) clypeus distinctly enlarged and produced anteriorly; (3) prementum distinctly emarginated apically; and (4) tentorial arms of head capsule enormously developed and strongly sclerotized.

Puparium. Brown, similar in size and form to third-instar larva, rather spindle-shaped, curved at each end; integumental spinules more prominent than on larva and anterior respiratory processes fully extended.

Biology.

All [taxon-name: Canacinae] from the New World occur in intertidal habitats and are sometimes called surf flies. Although the natural history of the subfamily is poorly known, the larvae and adults are probably grazers on algae or are saprophytic in both saline and freshwater habitats. In Brazil, all species of the subfamily [taxon-name: Canacinae] occur in the littoral biotic region.

Discussion.

Adult of [taxon-name: Canacinae] are similar and sometimes confused with shore flies ([taxon-name: Ephydridae]) and most species described in the 19th century were placed in the [taxon-name: Ephydridae]. Canacids are distinguished by the wing venation (cells bm and cup complete) and by the additional abdominal segments (5 in ephydrid males, 6 in canacids), which in females terminate as an elongate and fused epiproct+cercus that bears enlarged, apical setae.

The [taxon-name: Canacinae] now include 122 valid species that are placed in 11 genera (Wirth 1951; Mathis 1992; Munari and Mathis 2010). The New World fauna comprises five genera and 35 species (Wirth 1965, 1975, 1987; Mathis 1992). No fossils are known. Mathis’ catalog (1992) included all species then known plus references to papers containing keys and illustrations. The recent catalog of Munari and Mathis (2010) is a complete updating, including keys to all known genera. In the New World, Mathis (1989, 1997) reviewed the surf-fly fauna for the Caribbean and Gulf of Mexico.

Mathis (1982) proposed a classification for the [taxon-name: Canacinae]sensu stricto that should be revised. The subfamily includes two tribes, [taxon-name: Canacini] and [taxon-name: Nocticanacini]. The [taxon-name: Canacini] are represented in the New World by a single genus, [taxon-name: Canacea] Cresson, which belongs to the subtribe [taxon-name: Dynomiellina]. The [taxon-name: Nocticanacini] are represented by three genera in the New World, [taxon-name: Canaceoides] Cresson, [taxon-name: Nocticanace], and [taxon-name: Paracanace]. [taxon-name: Procanace], the fifth New World genus, was initially placed in [taxon-name: Nocticanacini], but it is now evident that this genus is the sister group to all other genera of the subfamily [taxon-name: Canacinae].

This is the most species-rich genus of surf flies ([taxon-name: Canacinae]; 35 species) and has greatest species diversity in the Old World (Mathis 1992). The New World fauna now comprises 14 species. The species known from Brazil belong to the pacifica, and galapagensis groups.

Annotated Key to Species Groups of the Genus [taxon-name: Nocticanace]

Discussion. The galapagensis group now comprises nine species with the addition of the new species described below. Previously, there were eight species ([taxon-name: Nocticanace arnaudi] Wirth, [taxon-name: Nocticanace cancer] Wirth, [taxon-name: Nocticanace curioi] Wirth, [taxon-name: Nocticanace darwini] Wirth, [taxon-name: Nocticanace galapagensis] (Curran), [taxon-name: Nocticanace scapanius] Wirth, [taxon-name: Nocticanace spinicosta] Wirth, and [taxon-name: Nocticanace usingeri] Wirth) that were only known from the Galápagos Archipelago and southwestern Nearctic Region. The discovery of [taxon-name: Nocticanace austra] from southern Brazil is a major range extension for this species group and perhaps indicates a more extensive distribution in southern South America for the group. Better sampling in southern South America is urgently needed to test this possibility.

Etymology. The specific epithet, austra, is of Latin derivation and means southern, referring to the distribution of this species in the Southern Hemisphere.

Remarks.

This species differs from congeners in the galapagos group in structures of the male terminalia, especially the shape of the surstylus (see figures and description above). The surstylus has a shallow, ventral bifurcation, somewhat like [taxon-name: Nocticanace wirthi], but is more narrowly developed, like [taxon-name: Nocticanace panamensis]. The anteroventral surstylar lobe is slightly longer than the posterior lobe.

Like [taxon-name: Canacea], all of the described species of [taxon-name: Paracanace] occur in the New World, with primarily tropical or subtropical distributions (Mathis and Wirth 1978).

Although two species groups are recognized in the key to species within [taxon-name: Paracanace], adhering to the cladogram for the species of this genus (Mathis and Wirth 1978: 535), these groups are mostly for convenience and no phylogenetic signal should be attributed.

This species is similar and evidently closely related to [taxon-name: Paracanace aicen] Mathis and Wirth from the West Indies, and these two species have been confused. Wirth’s original description and illustration of [taxon-name: Paracanace oliveirai], for example, included specimens of both species in the type series, and Wirth’s illustration, which is based on a specimen from the Dominican Republic, is actually [taxon-name: Paracanace aicen] (Fig. 7), not [taxon-name: Paracanace oliveirai] (Fig. 8). Because these two species have been confused, we present here comparable lateral views of the respective epandrium, surstylus, and cercus for both species to facilitate their identification. The illustration of [taxon-name: Paracanace oliveirai] is the first for that species. Please note that the lateral view of the fused surstylus of [taxon-name: Paracanace oliveirai] (Fig. 8) is more rectangular than the more elliptical shape of the comparable structure of [taxon-name: Paracanace aicen] (Fig. 7)

General coloration whitish gray, olivaceous, to blackish brown. Head: Interfrontal setae absent, but with a few setulae inserted anteriorly; fronto-orbital setae 3; ocelli arranged to form equilateral or isosceles triangle, if isosceles, the greater distance is between posterior ocelli. Arista pubescent over entire length. Two large dorsoclinate genal setae; anteroclinate genal seta moderately well developed. Palpus not bearing long setae. Epistomal margin, in lateral view, more or less horizontal. Thorax: Acrostichal setae, especially a prescutellar pair of large setae, usually lacking (setulae present in species of the williamsi group); scutellar disc lacking setae (1–2 pairs of scutellar disc setulae occur in [taxon-name: Procanace nakazatoi] Miyagi of the williamsi group); 2 pairs of marginal scutellar setae, apical pair not dorsoclinate; anterior and posterior notopleural setae present, length of both subequal; anepisternum with scattered setulae. Katepisternal seta usually present (lacking in species of the grisescens group). Hindtibia lacking spine-like setae apically. Abdomen: Male genitalia as follows: Epandrium in posterior view wider than high; cerci reduced, poorly sclerotized; surstylus with an anterior and posterior lobe, the latter larger, sometimes markedly so and shape unique to species.

Discussion.

Mathis (1988) first reported the occurrence of [taxon-name: Procanace] in the New World from specimens collected along the tidal shores of the Potomac River in Virginia. This species is now known from coastal habitats on Bermuda and from Virginia south through the West Indies to Brazil. Whether this species is adventive to the New World is unknown but likely.

The only species known from the New World is [taxon-name: Procanace dianneae], which is in the cressoni group of [taxon-name: Procanace] (Mathis 1988). The cressoni group is diagnosed by the following combination of external characters: Head: Postocellar setae present, subequal to length of ocellar seta; clypeus low, width at least 4X height; palpus yellowish. Thorax: Acrostichal setulae lacking; proepisternal seta(e) present; katepisternal seta present.

All specimens of the type series were collected from the shoreline of the tidal portion of the Potomac River at Westmoreland State Park (Virginia, United States). At the park, the river is over a mile wide, and the water is slightly brackish due largely to the tidal influence. The shore is either almost entirely sandy, the bathing area of the beach, or a combination of sand, considerable gravel, and some cobble and large rocks. In the latter habitat, the shore is quite narrow, at most two to three meters, and immediately adjacent to the shore is a cliff. In the sandy area, specimens occurred along the protected sides of narrow, wooden jetties that were installed perpendicular to the shoreline to break up the action of waves and prevent erosion of the beach. In the sand/cobble/rock habitat, specimens were found only on rocks and were easily collected by sweeping immediately over and between the rocks. Most of the rocks and jetties were covered in part with algae, and we suspect that the larvae of this species were feeding on them.

Remarks.

Much of the temperate and tropical Atlantic Coast of the New World has some of the busiest commercial waterways in the world, and we do not dismiss the possibility that this species was introduced in conjunction with the large volume of traffic on these waters.

This species has a demonstrated ability to disperse well. Although initially discovered in Virginia, where it occurs widely along the state’s maritime coast, the species has now been found from Delaware south to Florida, along the Gulf Coast (Alabama and Mississippi), and into the Neotropics (Cuba and Brazil). The records from the state of Paraná are the southernmost thus far.

[taxon-name: Tethininae] are mostly halobiont/thalassophiles, occurring in coastal marine habitats. Adults of thalassophilous species are commonly found in coastal marine habitats (Karl 1930; Munari and Vanin 2007), including the intertidal zone, wrack heaps (usually brown algae that are most abundant along temperate seashores bathed by cold currents), salt marshes, dune vegetation, and on salty soils or bare sand. We have also observed adults often in large numbers on carcasses of marine animals on beaches.

The immature stages of the subfamily are incompletely known. Ferrar (1987) provided some observations on the puparia of [taxon-name: Tethina grisea] (Fallén). Gorczytza (1988) reported on the spatial and seasonal distribution of some European species ([taxon-name: Pelomyiella mallochi] (Sturtevant), [taxon-name: Tethina albosetulosa] (Strobl), [taxon-name: Tethina illota] Haliday, [taxon-name: Tethina flavigenis] (Hendel), and [taxon-name: Tethina grisea] (Fallén)) from a study using color traps on the Frisian Islands of Mellum and Memmert. In nature, an abundance of individuals and a paucity of species sometimes characterize sandy sites where tethinids occur.

[taxon-name: Dasyrhicnoessa] is distinguished from other genera of the family by the following combination of characters: Head: Frons bearing some setulae in addition to larger setae; fronto-orbital and orbital setae usually with similar orientation, mostly reclinate or lateroclinate; fronto-orbital setae 3–4; paravertical setae more or less convergent. Head: Face lacking shiny tubercle above vibrissal pore; vibrissal seta present on apex of vibrissal angle. Eye mostly densely covered with small, pale, interfacetal setulae. Gena bare except for a ventral or nearly ventral row of setae (peristomal setae); gena narrow, about 1/8–1/3 eye height. Palpus and proboscis usually normally developed; clypeus small, if exposed not protruding anteriad beyond oral margin. Thorax: Scutum with numerous rows of coarse setulae arising from punctures; scutellar disc bare; postpronotum with 3 main setae, ventral seta curved upward; acrostichal setulae in two or more complete or nearly complete rows; prescutellar acrostichal setae present; scutellar disc bare except for marginal setae. Wing with costa not spinose; vein A1+CuA2 short, much shorter than discal cell; wing usually short, about twice as long as wide (less often 2.5–3.0 times); cell bm and discal cell distinct. Forefemur generally bearing an anteroventral ctenidial comb on distal third; mid and hind tibiae evenly setulose, lacking anterodorsal or posterodorsal setae. Abdomen: Tergites wider than long; tergite 6 well differentiated from short syntergosternite 7+8, the latter forming a dorsal pregenital sclerite. Male terminalia: Epandrium with a posterior (true) surstylus, articulating with sternite 10. In some species, articulating broadly with ventral margin of epandrium, in others, reduced and positioned more dorsad, along posterior margin of epandrium. Anterior process a surstylarlike lobe, not articulating with sternite 10 but only with anterior margin of epandrium. This lobe much reduced in some species (absent in [taxon-name: Dasyrhicnoessa platypes] Sasakawa) and positioned more or less medially along anterior margin of epandrium. Aedeagus long, sinuous, ribbonlike.

Discussion.

In the New World, a single species, [taxon-name: Dasyrhicnoessa insularis] (Aldrich), is known, and was probably introduced through human commerce. Woodley and Hilburn (1994) and Mathis and Munari (1996) first recorded this genus from the New World (as [taxon-name: Dasyrhicnoessa ferruginea] (Lamb)), and here we provide detailed locality data and descriptive documentation for the genus and the only known species that occurs there. We first discovered the genus and species on barrier islands off the coast of Belize and at the western margin of the Caribbean. Since then, we have found it in the United States (Florida), Mexico (Tabasco), on the Lesser Antilles (Dominica, St. Lucia, St. Vincent), and Bermuda in the western North Atlantic. The genus was probably introduced through human commerce and is now widespread throughout the Caribbean Region and perhaps beyond. Elsewhere, the genus occurs primarily within the Pacific and Indian Ocean basins where 25 species have been described thus far (Munari and Mathis 2010).

[taxon-name: Dasyrhicnoessa] is distinctive and is easily distinguished, especially from other genera of the subfamily [taxon-name: Tethininae], by the densely setulose eyes, prominent oral vibrissal seta, vibrissal angle lacking a shiny tubercle, an anterior surstylarlike lobe, and a posterior (true) surstylus in males.

[taxon-name: Tethina] is distinguished from other genera of the subfamily [taxon-name: Tethininae] by the following combination of characters: Head: Frons bearing some setulae in addition to larger setae; fronto-orbital and orbital setae usually with similar orientation, mostly reclinate or lateroclinate; fronto-orbital setae 3–4; postocellar setae more or less convergent (lacking in [taxon-name: Tethina lusitanica]). Face with shiny tubercle above vibrissal pore. Eye appearing bare, setulae very sparse or lacking. Gena bare (except for [taxon-name: Tethina pictipennis] and [taxon-name: Tethina lusitanica], which have scattered, inconspicuous setulae) except for a ventral or nearly ventral row of setulae; gena high in many species, height 0.50–0.75 that of eye height. Palpus and proboscis usually normally developed; clypeus small, if exposed not protruding anteriad beyond oral margin. Thorax: Scutum generally with more or less numerous rows of coarse setulae arising from punctures; scutellar disc bare; postpronotum with 3 or more setae, ventral seta curved upward; acrostichal setulae in two or more complete or nearly complete rows (lacking in [taxon-name: Tethina lusitanica]); prescutellar acrostichal setae present (lacking in [taxon-name: Tethina lusitanica]). Wing with costa not spinose; vein A1+CuA2 short, much shorter than discal cell; wing usually shorter, about twice as long as wide (less often 2.5–3.0 times); cell bm and discal cell distinct. Mid and hind tibiae evenly setulose, lacking anterodorsal or posterodorsal setae. Abdomen: Tergites wider than long; tergite 6 well differentiated from short syntergosternite 7+8, the latter forming a dorsal pregenital sclerite. Male terminalia: Surstylus positioned at ventral margin of epandrium, usually broadly articulated externally with epandrium, internally with subepandrial sclerite; aedeagus usually very long and sinuous, either thick and straplike or narrow and ribbonlike; aedeagus micropubescent dorsally.

Discussion.

Worldwide among genera of [taxon-name: Tethininae], [taxon-name: Tethina] has more than half of the described species (77 of 115) (Munari 2002). Two species occur in the study area and a third, [taxon-name: Tethina albula] (Loew), has been reported (Prado and Tavares 1966) but not seen as part of this study. Since [taxon-name: Tethina albula] has been reported from Brazil, and as there is the possibility of its occurrence there, we have included it in the key to species. The included species of [taxon-name: Tethina] occur along maritime beaches of the littoral biotic region. Specimens are sometimes abundant, especially on fresh and decomposing wrack.

Some slight variation was evident in the shape of the surstyli within specimens of this species. In posterior view the surstylus varies from being shorter and more exactly triangular to being slightly longer but still triangular. Previously we considered these differences to represent separate species, [taxon-name: Tethina bermudaensis] and [taxon-name: Tethina willistoni]. After examination of many dissected specimens from Canada south through southern Brazil, we agree with Foster and Mathis (2008) that this variation is intraspecific.

The variation in setal coloration and size of [taxon-name: Tethina willistoni] is remarkable. The variation in external characters is as follows: the more robust specimens from the Carribean areas have mostly stout, black setae and often present a very “bristly” habitus (similar to [taxon-name: Tethina spinulosa] and [taxon-name: Tethina horripilans]). Smaller, more delicate specimens have only the apical scutellar setae black with all other setae being white. Many specimens fall between these two extremes, making it virtually impossible to distinguish between [taxon-name: Tethina willistoni] and other species on the basis of external structures alone. A very similar chaetochromatic variation is also found in the Western Palearctic [taxon-name: Tethina albosetulosa] (Strobl) (Munari and Canzoneri 1992; Munari and Vanin 2007).

This widespread species can easily be distinguished from [taxon-name: Tethina cohiba] (often collected at the same locality) in having an obvious reddish yellow spot on the apex of the scutellum. Some specimens must be examined with the scutellum oriented to be directly viewed from behind and with good lighting. In most specimens, however, the spot is immediately obvious. Additional external characters include the mostly yellow femora, which are moderately swollen, as in [taxon-name: Tethina cohiba].

We gratefully acknowledge the assistance and cooperation of many organizations and individuals who contributed to the field work and production of this paper. To Carlos Lamas (MZUSP), who loaned specimens or provided access to collections during a recent visit, we express our sincere thanks. For reviewing the paper, we thank Lorenzo Munari and an anonymous reviewer.

Illustrations of the new species were expertly produced by Mirian Nunes Morales, who is gratefully acknowledged and thanked. Other illustrations were carefully inked by Young T. Sohn from pencil drawings. For reviewing a draft of this paper we thank Lorenzo Munari and Oliver S. Flint, Jr. The plates were assembled by Michael Biondi and Karolyn Darrow. The latter also expertly photographed and assembled the plate of head photos of [taxon-name: Nocticanace austra] (Figs 3–4) in addition to general enhancement of all plates.

Recent field work in Brazil (December 2009-June 2010) that resulted in the vast majority of specimens studied in this paper was supported by a grant from CNPq (Visiting Researcher/Process number 401609/2009–0), which we gratefully acknowledge and thank. We thank Dianne Mathis for helping with all aspects of the production of this paper, especially the field work in Brazil.

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McAlpine DK. (Year: 2007) The surge flies (Diptera, Canacidae, Zaleinae) of Australasia and notes on tethinids-canacid morphology and relationships.Records of the Australian Museum 57: 27-64doi: 10.3853/j.0067-1975.59.2007.1468

Wirth WW. (Year: 1965) Family Canaceidae. In: Stone A et al. (Eds) A catalog of the Diptera of America north of Mexico. United States Department of Agriculture, Washington, DC, Agricultural Research Service, Agriculture Handbook 276, 733–734.

Wirth WW. (Year: 1975) [Fascicle] 76. Family Canaceidae. In: Papavero N. (Ed). A catalogue of the Diptera of the American south of the United States.Museu de Zoologia, Universidade de São Paulo, São Paulo: 1-5

Frontal orbit with 3–5 major lateroclinate setae, foremost near level of ptilinal fissure, in addition to inner series of 3 or more proclinate-inclinate, shorter setae or setulae; proclinate-inclinate interfrontal setae in 2 distinct series; pair of convergent, often widely spaced, postocellar setae present; if absent then wing with distinct, black spots ([taxon-name: Tethina lusitanica]); costa along marginal cell with a continuous series of closely placed, short, black, anterior spinules, and no series of longer, widely spaced spines; discal and second basal cells separate; anal cell closed; vein A1+CuA2 (6th longitudinal) not extending distinctly beyond anal cell, even as a sharp fold in membrane

[taxon-name: Tethininae]

–

Fronto-orbital setae not arranged as above; if biseriate interfrontal setae present, then either convergent postocellar setae absent or anal cell open distally; other characters variable

2

2

Wing either vestigial, or with long vein A1+CuA2 extended to margin; fronto-orbital setae normally 3, of which middle one is reclinate and further from eye than others; female: syntergite 1+2 longer than rest of abdomen; endemic in the subantarctic archipelagos

[taxon-name: Apetaeninae] (not yet known from South America)

–

Wing normally developed, with vein A1+CuA2 scarcely extended beyond anal cell; if 3 fronto-orbital setae present, then middle one not farther from eye than others; syntergite 1+2 at most as long as or normally shorter than rest of abdomen; not inhabiting the subantarctic archipelagos

Acrostichal setulae in about 4 rows; surstylus narrow in lateral view, digitiform, slightly angulate; anterior margin of surstylus with few setulae, these not as long as those along posterior margin (Costa Rica: Cocos Islands)

Eyes densely though minutely setulose. A true vibrissal seta present on vibrissal angle (lacking shiny tubercle above the foremost strong peristomal seta). Male with an anterior surstylarlike lobe in addition to true surstylus, which is fused to epandrium in some species

[taxon-name: Dasyrhicnoessa] Hendel, 1934

–

Eye bare or sparsely setulose. A true vibrissal seta absent but foremost peristomal setae inclinate and simulating vibrissae (the bare vibrissal angle a shiny tubercle above each false vibrissae). Male lacking a surstylarlike lobe but with a true surstylus usually positioned ventrad of epandrium and articulating with it

[taxon-name: Tethina] Haliday, 1837

[TableWrap ID: d33e2687]

1

Gena short, 0.33 or less height of eye; setae and setulae black. Apex of scutellum with yellowish to reddish spot (may vary in size but always obvious)